AURORA, Colo. -- The Aurora Police Department says it is now treating the disappearance of a woman who was last seen in mid-December as suspicious.

Kyo Miller, 87, was reported missing by her friends on Dec. 15, 2018.

"Since then, Aurora Police Department investigators have been actively investigating her disappearance. Circumstances in this case now lead investigators to believe Mrs. Millers disappearance is suspicious," APD said in a Facebook post Thursday.

Kyo Miller. Credit: Aurora police

Miller was last known to be living with her ex-husband, 72-year-old Eldred Miller and his current wife, 53-year-old Galyna Miller. The three lived in the 3400 block of South Halifax Way, according to APD. The area is not far from the intersection of South Tower Road and East Hampden Avenue.

On Friday, APD spokesperson Officer Anthony Camacho said investigators have reached a point where they need the public's help.

"They have exhausted all the leads in this case and a lot of things they need to look into. They’ve been tracking down friends, looking into her background. Some of those things take some time and don’t happen as quickly as we’d like them to," Camacho said.

Anonymous tips can also be made to Metro Denver Crime Stoppers at: 720-913-7867. A reward of up to $2,000 is being offered.

“We are looking for any bit of information that anyone in the public may have, no matter how small it may seem or how significant they think it is. Any little bit can help tip this for our investigators, so that’s why we are asking for help," Camacho said, adding that investigators are especially concerned because of Miller's age and the possibility of health problems in the past.